Drive-permission apparatus

Abstract

An ECU controls a starter relay. Output angle detector detects a rotational angle of an output shaft in a rotary actuator. The ECU stores a first rotational angle which is detected by the output angle detector when a starting switch is OFF. When the starting switch is ON and when the difference between a second rotational angle detected at that time by the output angle detector and the first rotational angle already stored is not within a certain value, the ECU inhibits the operation of the starter relay to inhibit engine start.

1. A drive-permission apparatus comprising:
 a rotary actuator having an output shaft for outputting a rotational torque in order to actuate a shift range switching mechanism by use of an electric motor generating a rotational output when energized, the shift range switching mechanism directly or indirectly switching an actual shift range of an automatic transmission which shifts an output rotation outputted from an engine; 
 angle detecting means for detecting a rotational angle of a rotor of the electric motor or a rotational angle of the output shaft of the rotary actuator; 
 motor control means for controlling the operation of the electric motor to drive the shift range switching mechanism so as to change the actual shift range on the basis of the rotational angle detected by the angle detecting means; 
 memory means for storing a first rotational angle which is detected by the angle detecting means when the rotary actuator is OFF; 
 drive inhibiting means for inhibiting a start of operation of the engine when a command for the start of operation is given to the engine and when the difference between a second rotational angle detected by the angle detecting means and the first rotational angle stored in the memory means does not satisfy a predetermined condition; and 
 drive inhibition canceling means for canceling the inhibition of operation of the engine inhibited by the drive inhibiting means, wherein 
 while the drive inhibiting means inhibits the start of operation of the engine, the actual shift range of the shift range switching mechanism is brought to a vehicle non-start shift range, 
 a recognized shift range which the motor control means recognizes is brought to the vehicle non-start shift range, and 
 when the actual shift range and the recognized shift range are coincident with each other, the drive inhibition canceling means cancels the inhibition of operation of the engine. 
 
     
     
       2. A drive-permission apparatus according to  claim 1 , wherein
 the memory means is disposed in an interior of the motor control means, and 
 the memory means is either an Electrically Erasable Programmable Read Only Memory (EEPROM) able to store the first rotational angle even when an energization of the motor control means is stopped or a Static Random Access Memory (SRAM) able to hold the storage of the first rotational angle by receiving an electric current after the motor control means is deenergized. 
 
     
     
       3. A drive-permission apparatus according to  claim 1 , further comprising: fault detecting means for detecting whether the angle detecting means is at fault or not, the fault detecting means inhibiting the start of operation of the engine when a command for the start of operation is given and when the difference between the second rotational angle and the first rotational angle does not satisfy a predetermined condition or when it is detected that the angle detecting means is at fault. 
     
     
       4. A drive-permission apparatus according to  claim 1 , wherein
 the rotary actuator is constructed by the electric motor alone or by a combination of the electric motor and a reduction gear, 
 the angle detecting means detects a rotational angle of the rotor of the electric motor when the rotary actuator is constructed by the electric motor alone, or 
 the angle detecting means detects a rotational angle of the rotor of the electric motor or a rotational angle of an output shaft of the reduction gear when the rotary actuator is constructed by a combination of the electric motor and the reduction gear. 
 
     
     
       5. A drive-permission apparatus according to  claim 1 , wherein the angle detecting means detects the rotational angle of the output shaft of the reduction gear as a continuous quantity. 
     
     
       6. A drive-permission apparatus according to  claim 1 , further comprising: display/warning means which, when the drive inhibiting means inhibits the start of operation of the engine, provides indication or warning to a vehicle occupant that the start of operation of the engine is inhibited. 
     
     
       7. A drive-permission apparatus according to  claim 1 , further comprising: drive inhibition canceling means which, when the drive inhibiting means inhibits the start of operation of the engine, sets the actual shift range in the shift range switching mechanism to a vehicle non-start shift range, makes a recognized shift range which the motor control means recognizes and the actual shift range in the shift range switching mechanism coincident with each other so as to be the vehicle non-start shift range, and cancels the inhibition of operation of the engine inhibited by the drive inhibiting means. 
     
     
       8. A drive-permission apparatus according to  claim 1 , further comprising:
 drive inhibition canceling means which, when it is detected that a vehicular braking system has been actuated while the drive inhibiting means inhibits the start of operation of the engine, sets the actual shift range in the shift range switching mechanism to a vehicle non-start shift range, makes a recognized shift range which the motor control means recognizes and the actual shift range in the shift range switching mechanism coincident with each other so as to be the vehicle non-start shift range, and cancels the inhibition of operation of the engine inhibited by the drive inhibiting means. 
 
     
     
       9. A drive-permission apparatus according to  claim 1 , wherein
 the drive inhibiting means includes display means which indicates a start inhibition canceling method to a vehicle occupant when the drive inhibiting means inhibits the start of operation of the engine. 
 
     
     
       10. A drive-permission apparatus for use in a vehicle having control means for controlling the output of a motor-driven actuator to switch an actual shift range in a shift range switching mechanism installed in a vehicular automatic transmission, the control means being energized when a command for starting an engine is given, the control means being deenergized while the engine is OFF, the drive-permission apparatus comprising:
 actual shift range detecting means for detecting an actual shift range in the shift range switching mechanism; 
 memory means for storing a first actual shift range during stop of the supply of an electric current to the control means; 
 drive inhibiting means which inhibits the start of the engine when an energization of the control means is started and when a second actual shift range detected by the actual shift range detecting means and the first actual shift range stored in the memory means do not coincide with each other: and 
 drive inhibition canceling means for canceling the inhibition of operation of the engine inhibited by the drive inhibiting means, wherein 
 while the drive inhibiting means inhibits the start of operation of the engine, the first actual shift range of the shift range switching mechanism is brought to a vehicle non-start shift range, 
 the second actual shift range is brought to the vehicle non-start shift range, and when the first actual shift range and the second shift range are coincident with each other, the drive inhibition canceling means cancels the inhibition of operation of the engine. 
 
     
     
       11. A drive-permission apparatus for use in an apparatus having control means for controlling the output of a motor-driven actuator to control the operation of a shift range switching mechanism of an engine, the control means being energized when a command for starting an operation is given to an engine , the control means being deenergized while the engine is not in operation, the drive-permission apparatus comprising:
 actual position detecting means for detecting an actual position of the drive shift range switching mechanism; 
 memory means for storing a first actual position during stop of the supply of an electric current to the control means; and 
 drive inhibiting means which inhibits the start of operation of the engine when an energization of the control means is started and when a second actual position detected by the actual position detecting means and the first actual position stored in the memory means do not substantially coincide with each other and 
 drive inhibition canceling means for canceling the inhibition of operation of the engine inhibited by the drive inhibiting means, wherein 
 while the drive inhibiting means inhibits the start of operation of the engine, the first actual position is brought to a vehicle non-start shift range, 
 the second actual position is brought to the vehicle non-start shift range, and 
 when the first actual position and the second actual position are coincident with each other, the drive inhibition canceling means cancels the inhibition of operation of the engine. 
 
     
     
       12. A method comprising:
 outputting, from a rotary actuator having an output shaft, a rotational torque in order to actuate a shift range switching mechanism by use of an electric motor generating a rotational output when energized; 
 detecting a rotational angle of a rotor of the electric motor or a rotational angle of the output shaft of the rotary actuator; 
 controlling the operation of the electric motor on the basis of the detected rotational angle; 
 storing, in a machine-readable memory, a first rotational angle which is detected when the rotary actuator is OFF; 
 inhibiting a start of operation of a an engine related directly or indirectly to the shift range switching mechanism when a command for the start of operation is given to the engine and when the difference between a second detected rotational angle and the first rotational angle stored in the machine readable memory does not satisfy a predetermined condition; 
 canceling the inhibition of operation of the engine; 
 while the start of operation of the engine is inhibited, the second rotational angle is brought to a vehicle non-start shift range; 
 the second rotational angle is brought to the vehicle non-start shift range; and 
 when the first rotational angle and the second rotational angle are coincident with each other, the inhibition of operation of the engine is cancelled. 
 
     
     
       13. A method according to  claim 12 , wherein
 the machine readable memory is disposed in an interior of a motor controller which performs said controlling, and 
 the machine readable memory is either an Electrically Erasable Programmable Read Only Memory (EEPROM) able to store the first rotational angle even when an energization of the motor controller is stopped or a Static Random Access Memory (SRAM) able to hold the storage of the first rotational angle by receiving an electric current after the motor controller is deenergized. 
 
     
     
       14. A method according to  claim 12 , further comprising:
 detecting whether said detecting the rotational angle is at fault or not, and inhibiting the start of operation of the engine when a command for the start of operation is given and when the difference between the second rotational angle and the first rotational angle does not satisfy a predetermined condition or when it is detected that said detecting the rotational angle is at fault. 
 
     
     
       15. A method according to  claim 12 , wherein the rotational angle of the output shaft of the reduction gear is detected as a continuous quantity.